package jdbc0830;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class JDBCDemo6 {
    public static void main(String[] args) {
        try(Connection con=DBUtil.getConnection()) {

            Statement statement=con.createStatement();
            String sql="SELECT COUNT(*) count "+
                    "FROM class c "+
                    "JOIN student s ON s.class_id=c.id "+
                    "WHERE c.name='1年级1班' ";
            ResultSet rs=statement.executeQuery(sql);
            while (rs.next()){
                int count=rs.getInt("count");
                System.out.println("班级人数："+count);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}
